Spokeswoman Luba Samri says riots erupted in east Jerusalem and spread to Arab towns in the north today.
Protesters burned tires and threw rocks and fire bombs at police who responded with tear gas and stun grenades. More than 20 people were arrested.
Tensions have been high since three Israeli teenagers were abducted in the West Bank on June 12, sparking a huge manhunt that ended with the gruesome discovery of their bodies earlier this week.